Method of producing heat



C..E. LUCKE.

METHOD OF PRODUCING HEAT.

APPLICATION FILED SEPT-H, 1915. RENEWED AUG. 14.1919.

Patented June 22, 1920.

2 SHEETS-SHEET I.

C. E: LUCKE.

METHOD OF PRODUCING HEAT.

APPLICATION FILED SEPT-11,1915- RENEWED AUG. 14,19l9- 1,344,049, IPatented June 22, 1920. 4

2 SHEETS-SHEET 2.

2021175728555 I 7 Iii 72255? UNITED STATES CHARLES E. LUCKE, OF NEWYORK, N. Y.

METHOD OF PRODUCING HEAT.

Specification of Letters Patent.

Patented June 22,1920.

Application fileil September 11, 1915, Serial No. 50,189. Renewed August14, 1919. Serial No. 317,586.

To all whom it may concern Be it known that'I, CHARLES E. LUoKE, acitizen of the United States, residing at New York city, in the countyof New York and State of New York, have invented certain new and usefulImprovements in Methods of Producing Heat, fully described andrepresented in the following specification and theaccompanying drawings,forming a part of the same.

This invention relates to the production of heat by the burning ofexplosive gaseous mixtures continuously, or non-explosively, asdistinguished from non-continuous, or intermittent combustion-of suchmixtures.

The invention comprises a method wherein me March 22, 1904, there isdescribed and mation without diffusion with other gas by claimed amethod of burning explosive gaseous mixtures wherein the explosivemixture is caused to flow. with a velocity greater than the rate ofpropagation of inflammation of the mixture in order to prevent backflashing, a d the flow velocity is then reduced tothe rate ofpropagation of inflamcausing the flowing mixture to spread out with lossof flow velocity, and the mixture is then burned at the surface or zoneat which the flow velocity is equal to the rate-of propagation ofinflammation. In the apparatus shown in said patent for carrying out themethod there claimed a stream of mixture flowing with excess velocity isinjected into a porous and permeable bed of refractory,

material by which the flowing mixture is deflected and caused to spreadout as it passes through the passages of the bed.

The object of the present invention is to provide a method wherein thedesired rapid reduction of flow velocity of the mixture is securedwithout resort to the use of a porous and permeable bed through whichthe mixture is caused to flow or other deflecting or battling structure;and generally the invention aims to provide a method which shall beefficient and suited for general use, and especially adaptable for useunder conditions where the use of a porous and permeable bed ofrefractory material as a velocity reducing and combustion localizingmeans would be undesirable.

In accordance with the present invention, the reduction of the flowvelocity of the rapidly flowing mixture is secured by causing themixture to take the form of a laterally spreading free stream or jet,whereby without the interposition of any obstruction in its path of flowthe mixture will advance in a stream or jet of rapidly increasing cross-section and with correspondingly rapidly decreasing velocity. In such arapidly spreading free jet the reduction of flow velocity from avelocity largely in excess of the rate of propagation of inflammation ofthe supplied mixture to a velocity equal to the rate of propagation ofinflammation of the mixture at the place of combustion may be obtainedwithin a comparatively small distance from the place where spreadingbegins, and without suflicient diffusion with other gas between thepoint of mixture exit and the combustion zone to interfere withcommercial requirements of heating appliances. The flowing mixture isbest caused to take the form of a free rapidly spreading jet or streamby imparting to the mixture such direction or characteristic of flowbefore it leaves a discharge opening that on leaving the opening it willtake the desired form. By locating the jet between more or less closelyadjacent walls of refractory material preferably of low heatconductivity, the walls,- becoming highly heated, may serve as a sourceof radiant heat and also serve to accelerate the combustion of themixture and aid in localization of the combustion.

It will be understood that by the term explosive gaseous mixture as usedherein is meant a mixture of a suitable combustion supporting gas,either oxygen alone or air or other oxygen-containing gas, withcombustible matter in a gaseous or other finely divided state in properproportions, that is, in proportions such that the mixture will have theproperty of self-propagation of inflammation. For producing the highesttemperature, the oxygen should be undiluted and the mixture shouldcontain oxygen and combustible matter in chemical combining proportions;but there may be an excess of either the combustible matter or thecombustion supporting gas within the limits which determine the propertyof self-propagation. The mixture may be varied in this respect accordingto the desired character of the products of combustion, that is, whetherit is desired that the products shall be neutral, oxidizing or reducing.Also, the

tus or burner comprising a nozzle for discharging the explosive gaseousmixture in the form of a rapidly spreading jet which is like an ordinarycentrifugal spray nozzle for spraying liquids.

Fig. 2 is a similar view showing another form of nozzle or dischargingdevice.

Fig. 3 is a. section of the burner shown in Fig. 2 taken through thesupply passage and the tangential passages leading to the dischargeopening.

Fig. 4 is a sectional view of an open top furnace provided with devicesfor supplying the mixture in the form of rapidly spreading jets to burnwithin the furnace chamber. Figs. 5 and 6 are sectional views taken onlines 55 and (36 respectively of F ig. 4.

Fig. 7 is a sectional view of another form of burner.

Fig. 8 is a plan view of the burner shown in Fig. 7.

Referring to the drawings, and first to Fig. 1, the burner shown in thisfigure comprises a nozzle 10 which issimilar to a well known type ofcentrifugal spray nozzle used for spraying liquids. The. nozzle isprovided with spiral vanes 11 within its cylindrical body portion bywhich a rotary or spiral movement is given to fluid flowing through thenozzle, and has a velocity increasing tapering channel 12 beyond thevanes. Fluid discharged from the nozzle, by reason of its rapid rotarymotion ftakes the form of a rapidly spreading cone-shaped jet havingmore or less curved sides. The gaseous explosive mixture is supplied tothe nozzle through its inlet opening 13 under a pressure suflicient tocause it to be discharged from the mouth of the nozzle with the desiredexcess flow velocity from any suitable source or from any suitablemeans, as for example, by the means shown in Fig. 2 for supplying amixture of fuel gas and air.

The mixture discharged from the nozzle with a flow velocity greater thanthe rate of propagation of inflammation of the mixture will take, asabove stated, the form of a rapidly spreading free jet, advancing fromthe discharge opening, or nozzle mouth, with increasing cross-sectionand with decreasing flow velocity, or rate of advance away from thedischarge opening, without the aid of any bafiiing means. The flowvelocity of the mixture, that is, the rate or velocity of vance of themixture in the direction directly away from the discharge opening, isthus rapidly reduced so that, even when the mixture is discharged withan initial velocity greatly in excess of the rate of propagation ofinflammation of the mixture, reduction of the flow velocity to the rateof propagation of inflammation of the mixture may be attained within acomparatively short distance from the discharge opening and withoutdiffusion to any serious extent with the surrounding atmosphere eventhough the spreading jet be entirely unprotected. Combustion beingstarted, will continue at the surface or zone where the fiow velocityequals the rate of propagation of inflammation of the mixture as itreaches such surface or zone.

For most elficient operation, it is desirable to provide a wall ofsuitable refractory material of low heat conductivity extending aboutthe space in which the spreading jet is formed and within whichcombustion takes place, and such a wall is shown in Fig. 1 in which abody 15 of fire brick or other suitable refractory material of low heatconductivity is shown as formed with a flaring opening the sides ofwhich may extend more or less distant from the path of the sides of thespreading jet of mixture or so that the space between them is completelyfilled by the jet of mixture. Most desirably the walls extend so thatthe advancing mixture will fill the space between them, diffusion withsurrounding atmosphere being thus entirely prevented. The wall ofrefractory material surrounding the combustion space becomes highlyheated, and the resulting heating of the advancing mixture and thepresence of the incandescent solid matter increase the rate ofcombustion and the ca pacity of the burner and also aid in localizationof the combustion. The walls also become a source of radiant heat, andbeing of low heat conductivity protect from excessive heating the end ofthe nozzle and the plate 16 and prevent any possibility of conduction ofheat back to the low velocity chamber to such degree as might causeignition of the mixture therein.

Figs. 2 and 3 show a form of burner in which the spreading free jet ofexplosive gaseous mixture is produced by causing the mixture to flowthrough a plurality of passages 20 leading from an annular supplypassage or chamber 21 and opening tangentially into the dischargeopening 22 or periment.

mouth of the nozzle. The explosive mixture is supplied to the chamber 21through the inlet 23 under sufiicient pressure to cause the whirlingstream of mixture to advance from the discharge opening of the nozzlewith the desired excess velocity.

Reduction of fiow velocity or rate of advance from the dischargeopening, and localization of combustion where the flow velocity equalsthe rate of propagation of inflammation of the mixture within a shortdistance beyond the discharge opening, take place as with the burner ofFig. 1. burner of these figures is also shown as provided with flaringwalls of refractory ma terial of low heat conductivity surrounding thecombustion space. i

There is also shown in Fig. 2, but on a smaller scale than the burner, amixture supplying means comprising a tank G for fuel gas and a tank Afor air or oxygen or other combustion supporting gas. The fuel gas andcombustion supporting gas may be supplied to these tanks by any suitablemeans adapted to maintain the desired pressures therein. Outlet pipescontrolled by valves a and 9 lead from the tanks and connect with asupply pipe 24 which leads to the inlet 28 of the supply chamber. Thevalves a and g serve to control the proportions of fuel gas andcombustion supporting gas in the mixture, andthe pressure maintained inthe supply chamber and the velocity of flow through the supply passages20 may also be controlled by these valves. The proper proportions offuel gas and .combustion supporting gas, that is, proportions suchaccording to the nature of the constituent gases that the mixture shallhave the property of self-propagation of inflammatioinmay be readilydetermined by ex- The means shown and above described for supplying anexplosive mixture under the required pressure is, of course, onlyillustrative, and various other suitable means might be employed. Soalso, explosive mixtures other than mixtures, of fuel gas and air orother combustion supporting gas may be used in practising my method,such, for example, as explosive gaseous mixtures of air and coal dust orcharcoal dust or fine oil spray, mist or fog.

By removing the partitions between the passages 20 so as to have aconical slot extending from the supply chamber to the discharge opening,a jet'which first converges and then diverges or spreads may beproduced.

Another form of nozzle for producting a rapidly spreading jet of theexplosive gaseous mixture is shown in Figs. 4, 5 and 6, Fig. 4 showing afurnace provided with two such supply nozzles and having an open toppedchamber into the lower part of which the spreadingfree jets of explosivemixture The are injected to burn within the chamber. The furnace chamberis lined with highly refractory material of low heat conductivity whichis formed with openings registering with openings in the outer metal orother wall of the furnace through which the mixture is injected from thenozzles. These openings are most desirably of such shape as to limitdiffusion as hereinbefore explained. The nozzles are formed with aninlet or entrance passage 30 leading tangentially into an annularpassage 31 from which a converging passage 32 annular in cross-sectionleads to the discharge opening or mouth of the nozzle. The rotarymovement of the mixture due to its tangential entrance into the passage81 is increased as it passes through the converging passage 32, and themixture discharged from the nozzle takes the desired spreading jet formwith rapid reduction in its flow velocity as it advances from thedischarge opening, so that, the mixture being supplied to the nozzleunder pressure sufl icient to cause the desired. excess flow velocity atthe discharge opening, combustion will be localized a short distancebeyond the discharge 'opehing within the furnace chamber. When thefurnace is in operation all the interior surfaces of the furnace sweptby the extremely hot combustion gases will become heated to ahigh stateof incandescence.

Figs. 7 and 8 show an apparatus in which, instead of a conical spreadingjet of the gas eous mixture such as is produced by the devices shown inthe other figures, a flat spreading free jet is formed by the impactagainst each other of suitably directed unconfined streams of themixture. In this apparatus, the mixture for forming a spreading jet isdischarged from a pair of passages 40 in two streams which meet at asuitable angle to cause the mixture advancing from the place of impactto take the form of a flat spreading jet in a manner similar to that inwhich a fiat spreading jet is produced by the ordinary form of acetylenegas burner. The reduction of flow velocity in such a fiat spreading freejet is not so rapid as in a jet of conical form, but is sufiicientlyrapid for good results, especially when adjacent wall of refractorymaterial of low heat conductivity are provided. In

the apparatus shown by Figs. 7 and 8 a plurality of pairs of thepassages 40 lead from a supply chamber 41 and discharge into a spacebetween walls 42 of fire brick or other suitable refractory insulatingmaterial. The refractory insulating material extends also over the metalwall between the discharge ends of the passages 40 to protect the metaland especially the parts thereof adjacent the passages from becomingexcessively heated. An air passage 43 is also desirably provided to aidin preventing the metal from becoming undesirably heated. The explosivemix-- ture is'supplied to the chamber 41 through the inlet 44: underpressure sufficient to cause the mixture to flow through and to bedischarged from the passages with. a velocity greater than the rate ofpropagation of inflammation of the mixture.

lVhat is claimed is:

l. The method of burning explosive gaseous mixtures, which consists incausing the mixture to flow with an initial velocity greater than therate of propagation of inflammation of the mixture in the form of arapidly spreading free jet, whereby the flow velocity is rapidlyreduced, and burning the mixture where the flow velocity equals the rateof propagation of inflammation of the mixture.

2. The method of burning explosive gaseous mixtures, which consists in.dischargin a stream of mixture from an opening wit a velocity greaterthan the rate of propagation of inflammation of the mixture in the formof a rapidlyspreading free jet, whereby the flow velocity is rapidlyreduced, and burning the mixture where the reduced flow velocity hasbecome equal to the rate of propagation of inflammation of the mixture.

3. The method of burning explosive gaseous mixtures which consists indischarging a stream of the mixture from an openin with a velocitygreater than the rate of propagation of inflammation of the mixture andimparting to the stream of mixture before it is discharged a rapidrotary whirling movement, whereby the mixture when discharged is causedto take the formof a rapidly spreading free jet, its flow velocity beingthereby rapidly reduced, and burning the mixture where the flow velocityequals the rate of propagation of inflammation of the mixture.

4. The method of burning explosive gaseous mixtures, which consists indischarging a stream of mixture from an opening with a velocity greaterthan the rate of propaga tion'of inflammation of the mixture in the formof a rapidly spreading free jet into a space between walls of refractorymaterial of low heat conductivity, which extend closely adjacent thespreading jet to become highly heated by the burning of the mixture, andburning the mixture Where the flow velocity equals the rate ofpropagation of inflammation of the mixture.

5. The method of producing heat, which consists in mixing a fuel in afinely divided state with a combustion supporting gas in proportions toform an explosive gaseous mixture, discharging the mixture thus formedfrom an opening with a velocity greater than the rate of propagation ofinflammation of .the mixture and rapidly reducing the flow velocity ofthe mixture by causing the stream of mixture to take the form of arapidly spreading free jet, and burning the mixture where the reducedflow velocity has become equal to the rate of propagation ofinflammation of the mixture.

6. The method of producing heat, which consists in mixing a fuel in afinely divided state with a combustion supporting gas in proportions toform an explosive gaseous mixture, discharging the mixture thus formedfrom an opening with a velocity greater than the rate of propagation ofinflammation of the mixture into a space between flaring walls ofrefractory material of low heat conductivity in the form of a spreadingfree jet which fills the space between said walls, whereby the flowvelocity of the mixture is reduced to the rate of propagation ofinflammation of the mixture and diffusion with other gas is prevented,and burning the mixture.

In testimony whereof I have hereunto set my hand in the presence of twosubscribing witnesses.

CHARLES E. LUOKE.

Witnesses:

DAVID (J. LEWIS, A. L. KENT.

